Melanoma is a relatively common cancer, with stable or rising rates in the United States. Recent studies have identified genetics as an important contributor to risk, in addition to the well-established environmental risk factor of sun exposure. Self-examination is a potential method of identifying melanoma early enough to treat, and reducing sun exposure, especially in childhood, is a specific method of reducing risk of melanoma incidence. Both of these behavioral risk reduction behaviors need to be promoted, especially in individuals at familial risk for melanoma. We propose to identify cases of melanoma via an existing population-based registry to deliver behavioral and communications messages to the case and family members. We will randomize families to receive a Web-based intervention to help them through the experience of melanoma diagnosis, treatment, and recovery by emphasizing communications, support, information about risk, and changing health behaviors related to risk. This model of cancer-related behavior change intervention is potentially relevant to many different forms of familial cancer. The main aim of the randomized trial is to improve the sun exposure and self-examination behaviors of melanoma cases, first degree relatives, and the parents of children 0-18 via an intervention delivered through interactive electronic communication methods. Secondary intervention aims include determining the effects of this intervention on secondary outcomes from our behavioral model, identifying characteristics of user subgroups of relatives and relating these to outcomes, examining the acceptability of this intervention package, and determining the relationship between dose of intervention and effect of intervention. Aims addressing basic issues in communications are to identify perceptions and understanding of melanoma risk and family communication in melanoma cases, first degree relatives and parent and children, and relation to exposure related risk, general health risk, and health-related quality of life and to determine the effects of risk information framing on intentions to perform screening and sun exposure reduction behaviors.